An established and well-defined cohort of women with or at high risk for HIV infection will be expanded to study the natural history of human papillomavirus (HPV) infection and HPV-associated genital disease in women with HIV infection. Subjects will be recruited from among women participating in a research study of the natural history of HIV infection in drug users. This cohort will provide a unique opportunity to study the effects of HIV infection and host immunity and their interaction with other risk factors on the development and consequences of HPV infection. At six month intervals, subjects will undergo standardized interviews, physical examinations including pelvic examinations, PAP smears, tests for sexually transmitted diseases, and cervicovaginal lavage to collect cells for detection of HPV presence, type, and quantity as determined by Southern blot assay and polymerase chain reaction (PCR). Specific aims include: 1) Determine the incidence of and risk factors for genital HPV infection among HIV infected and uninfected high risk women, and use multivariate analyses to determine the importance of HIV infection, age, sexual behaviors, drug use habits, smoking, oral contraceptive use, parity, and degree immunosuppression as risk factors HPV infection, 2) Study the multifactorial causes for development of incident squamous intraepithelial lesions (SIL), with an emphasis on determining the role played by HIV infection, its associated immunosuppression on the natural history of HPV infection, 4) Determine whether the severity of cervical neoplasia at the time of diagnosis in HIV infected women screened by periodic PAP smears differs from that in women without HIV infection, and 5) Compare the outcome of treated cervical neoplasia in HIV infected women with that in high risk women without HIV infection, with regard to a) recurrent cervical neoplasia and b) associated immunosuppression on the natural histories of HPV infection and genital neoplasia. Using this information, the best approach to management of HPV-associated genital disease in HIV infected women will be determined. The study subjects will be comprised predominantly of women who are of minority ethnic and racial backgrounds and frequently immunodeficient; therefore they will likely be at particularly high risk for HPV infection and cervical neoplasia.